机械顶管施工中超挖和地面超载引起的地表沉降规律研究

Research on surface settlement regularity caused by over excavation and ground overloading in mechanical pipe jacking

结合某工程实例,对机械顶管施工中由于超挖和地面超载引起的地表沉降问题进行研究。按照现场实际条件确定参数,通过有限元软件建立顶管顶进模型并进行各工况模拟分析,然后将模拟结果与现场监测结果对比,以验证模型适用性。建立超挖量为30mm,地面超载为10kPa的顶进模型,模拟结果与现场监测结果基本吻合,验证了模型的适用性。分别改变单一影响因素,发现机械顶管施工中,超挖量和地面超载是影响地表沉降的两大重要因素。

Combined with an engineering example,the problem of surface settlement caused by over excavation and ground overloading in the construction of mechanical pipe jacking is studied.The parameters are determined according to the actual conditions in the field,and the jacking model of jacking pipe is established by finite element software and the simulation analysis of each condition is made.Then,the simulation results are compared with the monitoring results to ensure the applicaility of the model.A jacking model with an over excavation of 30mm and a ground overloading of 10kPa is established.The simulation results are basically consistent with the on-site monitoring results to verify the applicability of the model.Respectively,to change a single influencing factor,it is found that over-excavation and ground overloading are two important factors that affect surface settlement in the construction of mechanical pipe jacking.When the ground overloading is constant,the larger the over excavation is,the greater the settlement of the ground surface will be.When the over excavation is constant,the larger the ground overloading is,the greater the settlement of the ground surface will be.